A massive power breakdown on Wednesday hit large swathes of Punjab and Khyber-Pakhtunkhwa, depriving two-thirds of the country’s population of electricity for almost 10 hours.
Some technical fault either in one of the three major dams or the 500kV transmission lines triggered a domino effect and took the aging national grid down, suspending work at factories and businesses in the industrial heartland and highlighting the challenges successive governments have faced in getting to grips with chronic power shortages.
According to the Ministry of Water and Power (Power Division) spokesperson, Zafar Yab Khan, the breakdown was a result of some technical fault at Guddu-Muzaffargarh power line that caused tripping at major power plants, including Tarbela, Mangla, Guddu and Ghazi-Barotha hydropower plants.
Khan said, “Due to tripping of major plants, the north system had gone off affecting Khyber-Pakhtunkhwa and Punjab, resulting in electricity supply failure.”
However, the south system is working and there is no power supply failure to Sindh and Balochistan, he added.
This is the second major breakdown of the power system in May. On May 1, the power system had faced a breakdown following testing of the LNG-based power plants in Punjab, causing blackouts in some parts of the country.
A spokesperson for the Atomic Energy Commission said tripping at the main transmission lines also shut down all four units of the Chashma Nuclear Power Plant.
Power managers disclosed to the media that major cities — including Lahore, Sheikhupura, Faisalabad, Multan, Rawalpindi, Islamabad, Muzafargarh, Dera Ghazi Khan, Bahawalpur, Peshawar, Mardan and Swat — were affected owing to power breakdown.
Following the power failure, top management of the National Transmission and Distribution Company (NTDC), National Power Control Centre (NPCC), Ministry of Water and Power and officials of power distribution companies (DISCOs) rushed to NPCC to monitor maintenance and power restoration operation.
The Power Division has also notified an enquiry committee headed by Additional Secretary Waseem Mukhatar to ascertain the causes of tripping, the process of restoration and suggestions for system to avoid such incident in the future. The Additional Secretary will be assisted by three experts as member of the committee.
A preliminary report of the power failure states: “The electricity transmission system which split into north and south due to tripping today at 9:28am, resulting in the electricity supply failure to Punjab and K-Pareas was restored at 5:13PM (7:45 hours) with major power generation plants gradually increasing their input in the national grid.”
According to the initial report the 500kV transmission line Guddu 747-Raheem Yar Khan tripped at 09:28:11hrs and at the same time 500kV Guddu-Dera Ghazi Khan transmission line also tripped.
“As a result the load increased on 500kV Guddu-Muzaffargarh transmission line from 733MW/72MVAR to 1,559MW/717 MVAR as recorded at 500kV Muzaffargarh end.
“This line also tripped at 09:28:14hrs. This tripping resulted in under frequency on system from 50.18Hz to 48.755Hz within five seconds. Resultantly under frequency schemes came in action and frequency again improved from 48.755Hz to 49.43Hz at 09:28:38hrs.
“Meanwhile some other power stations also tripped perhaps due to frequency fluctuation/jerk and cascade tripping started in the northern pan from Guddu to Peshawar. The system went under partial failure from Guddu to Peshawar at 09:28:59 Hrs when frequency decayed down to 45 Hz. The Southern part of country from Guddu onward however remained normal during the entire day which includes Sindh and Balochistan areas.”
The southern parts of the country from Guddu onward; however, remained normal during the entire day which includes Sindh and Balochistan areas.
Speaking to The Express Tribune, spokesperson for the Peshawar Electric Supply Company (Pesco) Shaukat Afzal said an inquiry will be conducted to determine the reason for the fault.
It is important to note before the tripping, the system was having surplus electricity as compared to the demand; therefore, the temporary loadshedding was purely associated with the fault in the system.